The clinical manifestations if herpes simplex virus (HSV) infections range in severity from trivial epithelial infections to fatal encephalitis, as well as presenting an increasing public health problem in the AIDS epidemic. After the initial infection, the virus can reactivate from the latent state, producing episodes of disease. Latency is central to the natural history of the disease, yet the mechanisms involved in the processes of the establishment, maintenance, and reactivation of latent HSV are not understood. Understanding HSV latency is important for the control and possible elimination of the diseases caused by HSV. Addition, information providing an understanding of the regulatory mechanisms involved in HSV latency may provide insight into other viral diseases, such as AIDS, where complex host-virus interactions regulate the outcome of the infection. We developed a model of herpes simplex virus latency in neurons in vitro and showed that nerve growth factor deprivation results in the reactivation of latent virus. To elucidate the mechanisms involved in the control of HSV latency, the model of HSV latency in neurons in culture will be used to: (1) Analyze viral transcription during each phase of the infection, determine the state of the viral genome during latent phase of the infection and determine the effects of HSV latency on the physiology of the neuron; (2) identify critical HSV genes involved in the establishment, maintenance and reactivation of latency; (3) define the role of protein phosphorylation to latency and reactivation; and (4) examine cell extracts from neuronal cultures harvested under conditions which support latency or reactivation for the presence or absence of DNA binding factors.